Variable discharge pump



De.14,.19s4 f A. E. CRW. 2,696,790

VARIABLE DISCHARGE PUMP ATTORNEY Dec. 14, 1954 A. E. cR'ow 2,696,790

VARIABLE DISCHARGE PUMP Filed Oct. 23, 1951 4 Sheets-S1106?. 2

I N V EIN TOR. ,wos 5. mow

ATTORNEYS.

Dec. 14, 1954 A. E. CROW 2,696,790

VARIABLE DISCHARGE PUMP Filed oct. 23, 1951 4 shetssneet :5

INVENTOR. AMQS' E. c/ow Dep. 14, 1954 A. E. CROW 2,696,790

VARIABLE DISCHARGE PUMP Filed Oct. 23, 1951 4 Sheets-Sheet 4 INVENTOR.AMQS E. CROW BY umdm ammamg ATTORNEYS.

United States Patent O VARIABLE DISCHARGE PUMP Amos E. Crow, Long Beach,Calif.

Application October 23, 1951, Serial No. 252,658

8 Claims. (Cl. 10S-120) My invention relates to the eld of pumps, andmore particularly to a rotary type pump which may be adjusted to var therate of uid discharge whether the pump is operat ng or not.

,Control of the rate of fluid discharge from the pump of my invention isaccomplished by varying the radial position of the impeller bladesrelative to the eccentrically disposed housing in which they aremounted. Various types of pumps have been devised in the past thatembody the concept of radially movable blades, but the extent ofmovement of these blades is not controllable from outside the pump as ispossible with my device. Furthermore, the movement of the impellerblades in previously available pumps is dependent on unbalancedhydrostatic pressure existing on the fluid within the connes of thedevice.

The present invention dilfers from the prior art devices in a number ofrespects, the most important of which is the control of the position ofthe impeller blades by an auxiliary source of hydraulic lluid underpressure, and a manually operated cam mechanism. While my invention isadapted for the normal pumping operation, it is believed that itsgreatest utility will be found when associated with power vehicles toserve as a brake, or means of transferring the motive power from theengine to the driving portion of the vehicle.

A disadvantage common to all present-day pumping devices employingradially movable blades lies in the increase in pressure exerted on theblades due to contact with the interior surface of the housing as therate of impeller rotation increases. Thus, to prevent excessive wear onthe blades and interior of the housing it is necessary to operate suchpumps at relatively slow speeds. This disadvantage is completelyeliminated by the structural design of my pump which permits operationat any desired speed without regard to increased pressure between theblades and housing due to centrifugal force.

A major object of the present invention is to provide a pump in whichthe impeller blades may be radially adjusted to vary the rate of fluiddischarge by controlling the extent of possible outward movement of theblades, as well as the force which the blades exert on the interior faceof the housing.

Another object of my invention is to supply a pump in `which the extentof outward movement of the radially movable blades may be controlledfrom outside the pump either when the pump is operating or not.

A further object of my invention is to furnish a pump of a relativelysimple mechanical structure, that can be fabricated from commerciallyavailable materials, and operated at any desired speed withoutappreciably increasing the force with which the end portion of theimpeller blades contact the interior surface of the housing.

Yet another object of the invention is to provide a pump having avariable rate of fluid discharge that may be utilized as a brake on apower vehicle.

Yet another object of the invention is to supply a pump in which theblades may be completely retracted within the impeller portion of thedevice to permit lluid flow through the pump with little or noresistance from the impeller mounted therein when the blades are thuspositioned.

These and other objects and advantages of my invention will becomeapparent from the following description of a preferred form thereof,Aand from the drawings illustrating that form in which:

ICC

Figure 1 is a longitudinal vertical cross-sectional View of my pump;

Figure 2 is a transverse vetrical cross-sectional view of the devicetaken on the line 2-2 of Figure l;

.Figure 3 is a `diagrammatic transverse cross-sectional view of thedevice illustrating the manner in which it operates;

Figure 4 is an end elevational view of one of the movable impellerblades;

Figure 5 is a perspective view of one of the assembled impeller blades;

Figure 6 is a plan view of one of the assembled impellet blades;

Figure 7 is a perspective view of one of the rack members employed inrestricting movement of the blades;

Figure 8 is a fragmentary vertical cross-sectional view of the pumptaken on the line 8-8 of Figure l;

Figure 9 is a fragmentary vertical cross-sectional view of the pumptaken on the line 9-9 of Figure l;

Figure l() is a side elevational view of the rearward portion of a powervehicle with my pump installed on the drive shaft thereof to act as abrake;

Figure ll is a side elevational view of the rearward portion of a powervehicle with my pump installed thereon connected by gear means to thedrive axles;

Figure 12 is a vertical cross-sectional view of my pump taken on theline 12-12 thereof to show the manually operated cam means that controlthe extent of possible movement of the impeller blades; and

Figure 13 is a horizontal cross-sectional view of the cam mechanismtaken on the line 1.3-13 of Figure l2.

Referring now to Figures l, 2 and 3 for the general arrangement of mypump P, it will be seen that a shaft S rotatably supports an impeller Ihaving radially movable blades B within the contines of a housing H. Theinterior of the housing H is eccentrically disposed relative to theimpeller I. The rate of fluid discharge of the pump P is determined bythe radial position of the blades B as may best be seen in Figure 3,which will hereinafter be discussed in detail.

Housing H is preferably an elongate tubular shell 10 that has two endpieces 11 and 12 removably mounted thereon, held in position by bolts 13and 14 respectively. Shell 10 has a suction opening 15 formed in oneside thereof, and a fluid discharge opening 16 in the opposite side.Suction opening 15 is defined by a forked channel created by a rigidmember 17 of triangular vertical cross section, with the memberextending completely across the opening, as may best be seen in Figure2. A bar 18 of substantially rectangular cross section is similarlydisposed in discharge opening 16.

The interior annular vertical cross section of housing H iseccentrically disposed relative to the impeller I. The housing H ispreferably formed with an oversize interior cross section that isreduced to cooperate with the rotor R by inserting two segments 19 and20 therein as may best be seen in Figure 2. Two segments 17a and 18a ofarcuate cross section are disposed on the interior end faces of member17 and bar 18 to complete the reduction of the interior cross section ofhousing H.

impeller I is formed from a cylinder rotor 22 rigidly mounted on shaft10 and removably secured thereto by a key 23 as may be seen in Figure2l. Rotor 22 has four equally spaced slots 24 formed therein that extendinwardly substantially one-half the radius of the rotor. Each of theslots extend the entire length of the rotor, and each slot 24 has acentrally disposed passage 24a proceeding therefrom to bore 25 throughwhich the shaft S passes. From one end of the rotor 22 on which endpiece 12 is positioned, an annular cavity 25a extends inwardly tocommunicate with passages 24a at its inner end (Figure 8).

Cavity 25a has a ring 27 slidably mounted therein through which shaft Sextends. Ring 27 is formed with four equally spaced bores 28, each ofwhich has a curved groove 23a extending the length thereof. Fourelongate members 29 are provided that serve to regulate the outwardradial movement of blades B, with the members having pinions 30 disposedin slot extensions 24a. Shafts 31 extend outwardly from pinions 30 andare journaled in bores 31a formed in the rotor 22, as may be seen inFigure 1. Shafts 32 extend outwardly from the sides of the pinionsopposite those on which shafts 31 are mounted, and have transverselypositioned pins 32a formed thereon that slidably engage grooves 23a.Each of the members 29 vhas a helical spring 33 encircling shaft 32thereof, with the ends of the springs abutting against faces of therotor 22 and the interior face of ring 27. The helical springs 33 are atall times in compression, and tend to move the ring 27 away from pinions30, as may be seen in Figure 1.

The exterior portion of end piece 12 has abore 25h extendingtherethrough in which a portion of the shaft S is journaled. Bore 25aterminates on its interior end in an annular cavity 40 defined by avertical body shoulder 41 and .horizontal interior wall surface 42 ofannular configuration. The cavity 40 is in communication with a secondcavity 43 that extends outwardly from the face 12a of end piece 12, andhas a side wall 43a. An annular body shoulder 43h is formed at thejunction of cavities 40 and 43.

Ring 27 has a tube 44 extending outwardly therefrom. A portion of theshaft S is disposed within the confines of the tube. A flange 45 isformed on the outer end of tube 44 and disposed in cavity 40, as shownin Figure 1. An annular plate 46 is provided which has a centrallydisposed opening formed therein to permit mounting of the plate on tube44. Tube 44 is held in a non-rotatable position relative to shaft S by akey 47 and plate 46 is longitudinally movable in cavity 42.

Two ball bearing assemblies 48 and 49 adapted to take a thrust load aremounted on tube 44, with the plate 46 disposed therebetween. Bearing 48is disposed in cavities 25a and 43, with one face in contact with ring27 and the other with plate 46. The other bearing 49 is situated incavity 40, the two vertical faces thereof being in contact with plate 46and the flange 45.

Longitudinal movement of ring 27 on shaft S results in rotation ofpinions 30, the purpose of which will hereinafter be explained. Suchlongitudinal movement is accomplished by partial rotation of two spacedcams S mounted on shafts 51 journaled in bores formed in the end piece12, as may best be seen in Figures 12 and 13. Shafts 51 have pinions 52mounted thereon that mesh with gears 53 which are rigidly affixed to ashaft 54. The shaft 54 extends outwardly from the end piece 12, and isprovided with means (not shown) for manual rotation to the desiredamount.

A boss 55 is formed on end piece 12, and has a bore 56 formed thereinthrough which the shafts 12 extend. The threaded exterior 57 of the bossis engaged by a cap 58 which has a bore formed therein through whichshaft 54 extends. A fluid-tight seal is effected by tightening the capto compress a suitable packing member 59 disposed in bore 56 to such anextent that fluid cannot pass between it and the engaging portion of theshaft.

Each of the slots 24 has a rack 60 slidably movable therein, the teeth61 of which mesh with one of the pinions 30. Racks 60 each have a lug 62formed on the outer portion thereof substantially normal to thelongitudinal axis of the racks. The purpose of lugs 62 is to restrictthe possible outward radial movement of blades B as will be explainedlater in detail. Thus the rack and lug structure cooperate to provide astop that determines the maximum outward throw of the blade B with whichit is associated.

The detailed structure of blade B may best be seen in Figures and 6.Each of the blades includes two complementary members 70 and 70. As thestructure of each blade member is substantially identical, only one willbe described herein, with the corresponding parts of the other membersidentified by use of the same numerals to which a prime is affixed.

Blade member 70 includes a vertical end piece 71 from which an elongatebar 72 extends outwardly from the upper portion thereof. Bar 72 isnormally disposed to the longitudinal axis of end piece 70, and has arectangular slot 73 formed in the outer extremity thereof. A lug '74extending outwardly from end piece 71 is situated at substantially themid-point thereof, and extends in the same direction and disposeddirectly under bar 72. Lug 74 has a pin 75 extending from the extremitythereof.

The blade structure is mounted on an elongate member 76 radially movablein one of the slots 24, as may best be seen in Figures l and 2. Member76 has slots 77 and 77 formed therein in which lugs 74 and 74respectively are slidably mounted, and a longitudinally extending recess76 accommodates bars 71 and 71. The slots 77 and 77 `ha-ve bores 79 and-79 respectively, -extending inwardly therefrom in which the pins and75' are slidably movably. Bores 79 and 79 develop into extensions 79aand 79a that extend inwardly therefrom to terminate in communicationwith slot 24. Each member 76 has a centrally disposed recessed portion80 of substantially the width of slot extension 24a. The verticalcross-sectional configuration of portion 80 may best be seen in Figure2, and includes an elongate slot S1 defined by a wall portion 82 and twofingers 83 and 84. Slots 81 are slidably engaged by lugs 62, with thefingers 83 and 84 defining the possible radial movement of the blades B.

The use and operation of my invention is extremely simple. Asillustrated in Figure 1l, the pump is disposed on the rearward portionof a power vehicle V. Shaft S is connected by gear means, or othersuitable means (not shown), to the drive shafts which actuate wheels 91.Fluid is discharged from pump outlet 16 to a conduit 92 leading to asuitable member 93 provided with an orifice A. A conduit leads fromorifice A in member 93 to a leading to a suitable member 93 providedwith an orifice reservoir (not shown) connected to pump suction 15 bysuitable means.

When the pump P is actuated by rotation of wheels 91, fluid isdischarged through conduit 92 to orifice A that offers resistance to thepassage of fluid therethrough. The greater the volume of uid dischargedby the pump P to the aperture A, the greater the back pressure developedon fluid within housing H to further rotation of the impeller l. Shaft Sis geared to drive shafts 90, and as rotation of impeller l is lessenedby the fluid back pressure set up in housing H, the rotation of driveshafts 90 and wheels 91 is lessened. Thus, with a fixed orifice A mypump may be used as an auxiliary braking mechanism to slow down themovement of the vehicle on which it is mounted.

In the event the orifice A is adjustable in size, the operator of Vthevehicle first slows down movement of the vehicle by increasing thequantity of uid discharged through theorice, and then stops the vehicleby reducing the size of the orifice or completely closing it. Theoperation of my pump P as a brake on a vehicle is the same whetherconnected to the driving axles 90 as shown in Figure 11J or whenconnection to the drive shaft 95 as disclosed in Figure 10.

The vehicle V is provided with a source of hydraulic uid under pressure(not shown) that is connected by a conduit 96 to a bore 97 formed in endpiece 12. Bore 97 terminates in an aperture 97a formed in cavity sidewall 43a. A vacuum forming device (not shown) is also provided onvehicle V and connected by a conduit 98 to a bore 99 also formed in endpiece 12 that terminates in an aperture 99a formed in cavity side 43aadjacent the interior edge thereof, as best seen in Figure 1.

When disposed in the position illustrated in Figure l, plate 46obstructs aperture 99a. Plate 46 has bores 46a formed therein thatpermits fluid to flow from cavity 43 `to conduit 98 when the plate ismoved inwardly from the position in which it blocks aperture 99a.

The radial position of blades B is determined by manual adjustment ofthe shaft 51 which actuates cams 50 to longitudinally move plate 46within the confines of housing H. Movement of plate 46 results inconcurrent longitudinal movement of ring 27 on shaft 51. As ring 27 ismoved longitudinally on shaft 51, the pins 32a are rotated due toslidable engagement with grooves 28a, as may be seen in Figure 1.Rotation of pins 32a results in rotation of pinions 30, which due totheir engagement with racks 69, determine the positions of lugs 62.Blades B `and member 76 may move radially in slots 24, but with thedegree of movement restricted by the fingers 83 and 84 as shown inFigures 1 and 3. Outward movement of the members 76 is restricted by theengagement of fingers 83 with the lugs 62. Inward movement of themembers 76 on the rotor is restricted by the engagement of fingers 84with the lugs 62, as may be seen in Figure 1. The lugs 62 merelydetermine the possible degree of inward and outward radial movement ofmembers 76 relative to the supporting rotor.

After adjustment of the cam Sil to limit possible outward radial throwof blades B, hydraulic uid is admitted intopump P from conduit 96.Blades B are immediately forced outwardly until fingers 83 contact lugs62. Hydraulic iiuid passes through bores '79 and 79 and bore extensions79a and 79a to contact the extremities of pins 75 to force the blade endpieces 71 and 71 into lluid sealing contact with housing end pieces 11and 12 respectively.

Blades B are in the fully extended position for the partlcular settingof cam 50 prior to engaging segment 19, and thereafter retract untilthey are flush with the surface of rotor 22 when engaging segment 20.The quantity of h ydraulic fluid required to actuate the blades issubstantlally constant, for as one blade is moving outwardly, anotherblade is moving inwardly due to the offsetting of the interior ofhousing H.

When it is desired to reduce the quantity of iluid discharged from thepump, a portion of the hydraulic fluid supplied under pressure throughtube 96 is permitted to discharge through tube 98 to the reservoir (notshown) connected to pump suction 15. Cam 50 is then actuated to restrictthe possible outward throw of bladesvB until the rate of fluid dischargefrom the pump of my invention is reduced the desired amount.

From experience it has been found that my invention may be usedadvantageously in a closed hydraulic circuit where there is fluid ilowbut from a source other than my pump. Under these conditions it isdesirable that the blades B offer a minimum of resistance to fluid flow,which is accomplished by rotating cams 50 until the blades B arecompletely retracted into the rotor 22. The shaft S at all times rotatesthe rotor 22, but when the blades are fully retracted, little or nopumping action results. When it is desired to pump luid in such a closedhydraulic circuit, such as when used as a brake (shown in either Figuresl0 or ll) the cams 50 are rotated the desired amount, and iluid underpressure admitted through tube 96 moves the blades B outwardly.

Although the adjustable discharge pump herein shown and described isfully capable of achieving the objects and providing the advantageshereinbefore mentioned, it is to be understood that it is merelyillustrative of the presently preferred embodiment of my invention, andthat I do not mean to limit myself to the details of construction hereinshown other than as defined in the appended claims.

I claim:

1. A variable discharge rotary pump which includes: a cylindricalhousing with uid discharge and suction openings formed therein; a rotordisposedin said housing, said rotor having a plurality of radiallydisposed slots formed therein, and said slots communicating with acentrally disposed passage formed in said rotor; a plurality of blades,each of which is formed with two interlocking portions that may movelongitudinally relative to one another; a shaft rotatably supported insaid housing onwhich said rotor is mounted, saidshaft and rotor beingeccentrically arranged relative to said housing; a plurality of rigidmembers movably mounted in said slots two portions that are slidablyconnected to one another for longitudinal movement, each of saidportions being formed with an inwardly extending end piece from which apin projects; a plurality of rigid members movably mounted in said slotscapable of radial movement relative to said rotor, with one of saidblades being disposed along the outer longitudinal edge of each of saidmembers and with two bores being formed on the ends of each of saidmembers, which bores are in communication with said passage and slidablyreceive said pins; a plurality of radially movable stops, each of whichis disposed in one of said slots, with each of said stops including arigid portion that engages one of said members after said member hasmoved radially outwardly a predetermined distance relative to saidrotor; manually operated cam means that concurrently regulate the radialpositions of all of said stops; means to introduce hydraulic iluid intosaid passage to force said members outwardly into contact with saidstops, with a portion of said hydraulic fluid flowing through said boresto engage said pins and force the ends of said blade portions intofluid-sealing contact with the interior surface of said housing; andvacuum means for withdrawing said hydraulic fluid from said passage andbores to cause said blade portions to move inwardly a predeterminedlongitudinal distance toward one another, with said blades andsupporting members moving radially inward relative to said rotor toretracted positions.

3. A variable discharge rotary pump which includes: a cylindricalhousing with fluid discharge and suction openings formed therein; ashaft; a cylindrical rotor mounted on said shaft, which shaft and rotorare rotatably supported in said housing and eccentrically arrangedthereto, said rotor having aI plurality of parallel radially disposedslots formed therein, and said slots communicating with a centrallydisposed passage formed in said rotor; a plurality of blades supportedfor radial movement in said slots, each of said blades including twointerlocking portions that may move longitudinally relative to oneanother; a plurality of radially movable stops, a portion of each beingdisposed in one of said slots, with each stop preventing further outwardradial movement of one of said blades after said blade has movedoutwardly a predetermined distance relative to said rotor; manuallyoperated cam means that concurrently regulate the radial positions ofall of said stops; hydraulic means to force all of said blades radiallyoutward until further movement is prevented by said stops, and to moveall of said blade portions longitudinally into fluid-sealing contactwith the interior surface of said housing; and vacuum means to move saidblades radially inward relative. to

capable of radial movement relative to said rotor, with each of saidmembers so supporting one of said blades that said interlocking portionsmay move longitudinally but not radially relative to said supportingmember; a plurality of radially movable stops, each of which is disposedin one of said slots, with each of said stops including a rigid portionthat engages one of said members after said member has moved outwardly apredetermined distance relative to said rotor; manually operated cammeans that concurrently regulate the radial positions of all of saidstops; means to introduce hydraulic fluid into said passage to forcesaid members outwardly into contact with said stops, with a portion ofsaid iluid flowing through passage means extending outwardly from saidpassage to contact said blade portions and force the ends thereof intolluid sealing contact with the interior surface of said housing; andvacuum means for withdrawing said hydraulic iluid from said passage andpassage means to cause said blade portions to move inwardly toward oneanother a predetermined longitudinal distance, with said blades andsupporting members moving radially inward relative to said rotor toretracted positions.

2. A variable discharge rotary pumpwhich includes: a cylindrical housingwith fluid discharge and suction openings formed therein; a shaft; arotor mounted on said shaft, which shaft and rotor are rotatablysupported in said housing and eccentrically arranged relative thereto,said rotor having a plurality of parallel radially disposed slots formedtherein, and said slots communicating with a centrally disposed passageformed in said rotor; a plurality of elongated blades, each of which isformed from said rotor, and to move said blade portions inwardlyrelative to one another to a predetermined retracted position.

4. A variable discharge rotary pump which includes: a cylindricalhousing with iluid discharge and suction openings formed therein; ashaft rotatably supported in said housing; a rotor rigidly mounted onsaid shaft which shaft and rotor are rotatably supported within theconfines of said housing and eccentrically disposed relative thereto; aplurality of blades, each of which is formed of two portions with eachblade being supported from said rotor for radial and longitudinalmovement relative thereto; a plurality of adjustable stops mounted onsaid rotor, each of which is operatively associated with one of saidblades, the position of each stop controlling the maximum outward throwof said blade with which it is associated; manually operated means thatconcurrently adjust all of said stops to identical radial positionsrelative to said rotor; means to subject said blades to hydraulicpressure whereby said blades move outwardly relative to said rotor untilfurther movement is prevented by said stops, said blade portions beingso constructed that they move relative to one another to engage theinterior surface of said housing with a movable fluid-tight seal; meansto regulate the intensity of said hydraulic pressure to control thepressure with which said blades engage the interior surface of saidhousing; and means to subject said blades to a vacuum to withdraw saidblades to retracted positions relative to said rotor.

5. A variable discharge rotary pump which includes: a cylindricalhousing with fluid discharge and suction openings formed therein; ashaft; a cylindrical rotor mounted on said shaft, which shaft and rotorare rotatably supported in said housing and eccentrically disposedrelative thereto; a plurality of blades, each of which is formed of twoportions, with each blade being radially and longitudinally supported onsaid rotor; a plurality of adjustable stops, each of which isoperatively associated with one of said blades, the position of eachstop controlling the maximum outward throw of said blade with which itis associated; manually operated means that concurrently adjust all ofsaid stops to identical positions relative to said shaft; means tosubject said blades to hydraulic pressure whereby said blades moveoutwardly relative to said rotor until further movement is prevented bysaid stops, said blade portions being so constructed that they moverelative to one another to engage the interior surface of said housingwith a movable fluid-tight seal; means to regulate the intensity of saidhydraulic pressure to control the pressure with which said blades engagethe interior surface of said housing; and means to subject said bladesto a vacuum to withdraw said blades to retracted positions relative tosaid rotor.

6. A variable discharge rotary pump which includes: a cylindricalhousing with uid discharge and suction openings formed therein; a shaft;a cylindrical rotor mounted on said shaft, which rotor and shaft arerotatably supported in said housing and eccentrically arranged relativethereto, a plurality of blades rotatably supported within the confinesof said housing on said rotor, with each of said blades including twoportions that may move radially and longitudinally; a plurality ofadjustable stops operatively associated with said blades that determinethe maximum radial throw of said blades; manually operated means thatconcurrently adjust all of said stops to positions where the maximumradial throw of said blades are identical; means to subject said bladesto hydraulic pressure whereby said blades move radially outward themaximum distance permitted by said stops, said blade portions being soconstructed that they move relative to one another to engage theinterior surface of said housing with a movable Huid-tight seal; meansto regulate the intensity of said hydraulic pressure to control thepressure with which said blades engage the interior surface of saidhousing; and means to subject said blades to a vacuum to withdraw saidblades to retracted positions relative to said rotor.

7. A variable discharge rotary pump which includes: a cylindricalhousing with fluid discharge and suction openings formed therein; afirst shaft; a cylindrical rotor mounted on said shaft, which rotor andshaft are rotatably supported in said housing and eccentrically disposedrelative thereto, said rotor having a centrally disposed longitudinallyextending passage formed therein from which a plurality of radial slotsextend, with inwardly extending passages leading from said slots to saidlongitudinal passage; a plurality of blades, each of which is formed oftwo interlocking portions that move longitudinally relative to oneanother; a plurality of rigid members movably mounted in said slotscapable of moving radially relative to said rotor, with each of saidmembers so supporting one of said blades that said portions thereof maymove longitudinally but not radially relative to said supporting member;a plurality of radially movable stops formed with toothed racks, eachstop being slidably disposed in one of said inwardly extending passages;a plurality of pinions, each of which is disposed in one of saidinwardly extending passages and engages one of said racks; a pluralityof second shafts supporting said pinions on the ends thereof, with saidsecond shafts rotatably supported in said rotor; a plurality of pins,each of which is transversely disposed on the outwardly extended end ofone of said second shafts; a plate longitudinally movable on said firstshaft, said plate being formed with a plurality of curved and slottedbores, and said slotted bores being slidably engageable with one of saidpins; manually operated cam means which when actuated moves said platelongitudinally on said first shaft to rotate said pinions, and radiallymoves all of said stops the same distance; means to introduce hydraulicuid into said passageto force said members outwardly into contact withsaid stops, with a portion of said Huid flowing through passage meansextending outwardly from said centrally disposed passage to contact withblade portions, forcing the ends of said portions into huid-sealingcontact with the interior surface of said housing; means to control thepressure exerted by said hydraulic Huid regulating the intensity withwhich said blades are urged into contact with the interior surface ofsaid housing; and vacuum nieans to withdraw said hydraulic Huid fromsaid passage and passage means, causing said blade portions to move apredetermined longitudinal distance toward one another, and said bladesand supporting members to move radially inward relative to said rotor toretracted positions.

8. A variable discharge rotary pump which includes: a rotor; a shaft onwhich said rotor is mounted; a housing in which said rotor and shaft arerotatably supported and eccentrically arranged relative thereto; aplurality of blades mounted on said rotor in spaced relationship, eachof which is formed from two portions that are so const ructed that theymay move both radially and longitudinally relative to said rotor;manually adjustable means which restrict the outward and inward radialmovement of said blades relative to said rotor; hydraulic means to movesaid blade portions longitudinally and radially outward from said rotorwhereby said blade portions contact the interior surfaces of saidhousing; means to regulate the intensity of the force applied to saidblade portions by said hydraulic means; and vacuum means to Withdrawsaid blade portions inwardly toward said rotor to retracted positionsdetermined by the location of said adjustable means at the time of saidwithdrawal.

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